Water fluoridation device



March 20, 1962 R. w. woLFE 3,025,876

WATER FLUORIDATION Dax/ ICE Filed Oct. 2, 1959 2 Sheets-Sheet 1 Robert W Wo/fe IN VEN TOR.

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March 20, 1962 R. w. woLFE WATER FLUORIDATION DEVICE 2 Sheets-Sheet 2 Filed Oct. 2, 1959 Roberf W Wo/fe INVENTOR.

3,025,876 WATER FLUORIDATION DEVICE Robert W. Wolfe, Belton, M0. (329 S. Dallas Ave., Pittsburgh 8, Pa.) Filed Oct. 2, 1959, Ser. No. 844,123 7 Claims. (Cl. 137-5645) The present invention generally relates to a fiuoridation device and more particularly a domestic water fiuoridation device which provides for a constant proportion of additive or secondary fluid to the flow of the primary fluid such as water.

In prior patents, fluid proportioning devices have been disclosed which operate on the principle of introducing an obstruction in the primary fluid line in vthe form of an orifice, venturi tube, a Pitot tube or the like which obstruction then causes a static pressure drop in the main line. Pressure taps are situated in the main line to sense this pressure drop and tubes are attached to the pressure taps and are connected to an enclosed tank in which is contained the secondary fluid. The pressure difierence in the main line is exerted upon the secondary fluid through an interposed piston or diaphragm or the like and the pressure ditferential causes the secondary fluid to flow into the primary line through the pressure taps on the low pressure side of the obstruction. While such devices appear to be properly set forth, these devices ignore the dynamic qualities of various fluids. Therefore, it is the primary object of the present invention to provide a fluid proportioning device that is quite accurate and maintains the proportion of secondary fluid to primary fluid constant throughout the range of operation and the device is particularly applicable to fiuoridating the water of individual households for the purpose of the retardation of tooth decay with the fiuorine being added in about one part per million.

The present invention incorporates the provision of a localized enlargement in the main flow line provided with a porous obstruction together with capillary tubes extending outwardly on the high and low pressure sides of the porous obstruction for causing flow of secondary fluid or fiuorine from a container by providing pressure in a confined chamber with their being a fiexible separator, bag or the like for separating the primary and secondary fiuids so that the pressure of the primary fluid entering the tank from the capillary tube will force the secondary fluid out of the tank through the capillary tube for discharge on the low pressure side of the obstruction.

Another feature of the present invention is the provision of an larrangement in which a discharge flapper valve is provided for the secondary fluid which will close when no flow of the fiuid occurs which also shuts oif the secondary fluid at its extreme outlet so that no concentration can occur at zero flow from any secondary fluid remaining in the tube thereby assuring exact proportion even when the primary fluid fiow is intermitte-nt.

Yet another important feature of the present invention is to provide a fluid proportioning device which is readily mounted on a domestic water supply line and which may have a replaceable component easily removed and replaced.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a side elevation of the water fiuoridation device of the present invention;

FIGURE 2 is a longitudinal, sectional view illustrating the construction of the porous obstruction and the local enlargement in a water line;

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FIGURE 3 is a sectional view of the tank having the diaphragm and secondary fluid therein;

FIGURE 4 is a detailed sectional view taken substantially upon a plane passing along section line 4-4 of FIGURE 2 illustrating the construction of the flapper valve in relation to the porous obstruction; and

FIGURE 5 is an enlarged fragmental view illustrating the manner in which the secondary fluid enters the capillary tube adapter immediately adjacent the upper end of the diaphragm.

Referring now specifically to the drawings, the numeral 10 generally designates the fluid proportion or fluoridation device of the present invention which is installed in a primary fluid pipe which may conveniently be a household water line 14 which is preferably a cold water pipe on the downstream side of the hot water lead in the interest of economy. The device includes an enlarged chamber generally designated by the numeral 16 installed in the line 14 and a tank generally designated by the numeral 18 disposed in spaced relation thereto.

FIGURES 2 and 4 illustrate the details of construction of the chamber 16 which is in the form of a generally enlarged hollow housing or casing 20 having longitudinally extending nipples 22 and 24 attached to the pipe line 14 by any suitable means such as a screw threaded connection 26 or a soldered connection or the like.

A transversely extending porous member or obstruction 28 divides the housing 20 into two `separate halves or chambers 30 and 32. The Chamber 30 is provided with a pressure tap or fitting 34 having a passageway 36 therein which passageway communicates with the cham- 'ber 30. Connected to the pressure tap 34 or the fitting is a tube 38 and a needle valve 40 is provided for selectively opening and closing the passage 36.

The pressure tank or vessel 18 is shown specifically in FIGURES 3 and 5 and includes an enlarged hollow tank or vessel 42 having a screw threaded plug 44 in the upper end thereof which plug has a passageway 46 communicating with a passageway 48 and a valve body 50 having a needle valve 52 extending into the passageway 48. The passageway 48 is communicated with the tubes 38 for admitting pressure into the tank 42 through the passageway 46. The plug 44 is provided with a cylindrical portion 54 extending below the top wall of the tank 42 With the cylindrical portion 54 having a peripheral rib 56 for receiving the mouth of a flexible bag 58 which may be considered a diaphragm which has the mouth end thereof secured in position by an annular ring member 60. The diaphragm 58 separates the tank into two chambers designated by the numerals 62 and 64 with the' Chamber 64 containing secondary fluid or fiuorine while the Chamber 62 receives primary fluid or water. The balloon or bag-like diaphragm 58 is sized so as to be able to completely fill the pressure vessel without distending so that it transmits pressure from the primary to the secondary fluid but does not exert any pressure itself.

The secondary fluid in the cham'ber 64 communicates with a lateral pass'ageway 66 in the cylindrical projection 54 above the upper edge of the diaphragm 58 with the passageway 66 in turn communicating with a Vertical passageway 68 communicating with the passageway 70 in a valve body 72 having a needle valve 74 therein. The passageway 70 communicates with a capillary tube 76. The tube 76 extends to and 'is connected to a valve body 78 having a passageway 80 therein with a needle valve 82 seleetively closin'g the passageway and the valve body or pressure tap 78 is communicated with the downstrearn side of the porous member 28 which faces the eh-amber 32 and communicates with the same by virtue of an angled discharge member 84. The opening in the right angled discharge member 84 is closed by a flapper valve 86 carried by the strap spring or leaf spring 88 mounted on the porous member 28. The porous member 28 is provided with a cylindrical sleeve 90, extending therethrough lwhich provides a passageway therethrough with the discharge end of the passageway being closed by a fiexible diaphragm 92 which tests against the inner surface of the spring 88. When the primary fiuid is flowing, the pressure drop results across 'the porous member and the pressure difierence acts on the diaphragm 92 which in turn pushes against the lightly sprung fiapper valve 86 thereby opening the secondary fiuid inlet lport and the discharge member 84. When primary fiuid is not fiowing, the flapper valve 86 will be sealed for closing the discharge port for the secondary fiuid.

The casing or housing is provided with a drain petcock 94 which allows any sediment to be drained from the casing 20. A transverse screen or filter 96 is provided on the downstream side of the petcock 94 whereby the petcock 94 will drain any sediment or foreign material `collected in front of the screen 96. The screen 96 prevents the porous member from being contaminated by foreign ma-terial which might alter its fiow rate-pressure drop proportionality. The valves 40 and 82 are for the purpose of shutting off the pass-ageways when the pressure vessel or tank 18 is being replaced for replenishing the supply of secondary fiuid.

In operation, fiow of primary fiuid such as water in the pipe 14 produces a pressure drop across the porous member 28. This pressure differential acts through the tubing and pressure vessel resulting in a flow of secondary fiuid into the downstream side of the porous member where it mixes with the primary fluid. The flapper valve 86 shuts off the secondary fiuid at its extreme outlet so that no concen-tationcan occur -atv zero fiow from any r'esidual secondary fiuid remaining in the capillary tube. This assures exact proportioning even when the primary fiuid flow is excessively inter'mittent.

The enlargement of the primary fiuid fiow -line 14 'as formed by the casing 20 reduces the Velocity through thelporou's member in order to keep the pressure drop in -the primary line to a minimum 'and to assure that fiow through the porous member is laminar rather than turbulentvthereby producing a pressure drop which is linearly proportional to fiow. With a given secondary fluid capillary tube diameter and length a Constant ratio of primary to secondary fiow may be set up. The magnitude of this Constant ratio is readily altered by changing the length of the capillary tube in the secondary fiuid circuit. However, vfor a given geometry, the ratio of primary to secondary fiow stays constant over a wide range of flow from zero up to a known maximum valve when the primary flow changes from the laminar to the turbu'lent regime.

The geometry of the tubing and other structure is sized to give the recommended eoncentration of fiuorine of approximately one part per million. For water Supplies already containing some fiuorine, the geometry can be sized -to provide a supplementary quantity of fluorine. In view of the Very weak concentration required, a reasonably sized vessel Will provide a fiuorine supply for a very long period of time and when it is finally exhausted, the four needle valves may be closed and the pressure vessel uncoupled and a full pressure vessel may be installed in lieu thereof.

The foregoing is considered `as illustrative only of the principles of the invention. Further, since numerous modifications and 'changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed las new is as follows:

1. A fiuid proportioning device for introducing a secondary fluid in a substantially constant proportion into a primary fiuid comprising a hollow casing interposed in the fiuid fiow vline of the primary fiuid, a transversely extending porous member dividing the casing into two compartments with the upstream compartment having a higher pressure than the downstream compartment thereby providing a pressure differential on opposite sides of the porous member, a hollow tank disposed in spaced relation to said casing, said hollow tank including a fiexible non-stretchable diaphragm, the portion of the tank outwardly of 'the diaphragm ad'apted to contain secondary fiuid, lmeans communicatin'g the high pressure compartment of the casing With the interior of the diaphragm for pressurizing the diaphragm with high pressure from the upstream compartment, means communicating the portion of the tank exteriorly of the diaphragm with the low pressure compartment of the casing for admitting secondary fiuid into 'the downstream compartment, said last named means including fiow restriction means comprising a capillary .tube in communication with a port in the downstream compartment of the casing for restricting the fiow of secondary fluid, and means closing the port leading into the downstream chamber from the fiow restriction means for preventing residual fiow of secondary fiuid into -the downstream compartment when there is no primary fiuid fiow.

2. A fiuid proportining device for introducing a secondary fiuid in a substantially Constant proportion into a primary fiuid comprising a hollow casing interposed in the fiuid fiow line of the primary fiuid, a transversely extending porous member dividing the casing into two compartments with the upstream compartinent having :a higher pressure than the downstream compartment thereby -providing a pressure differential on opposite sides of the porous member, a hollow tank disposed in spaced relation to said casing, said hollow tank including a flexible non-stretchable diaphragm, the portion of the tank outwardly of the diaphragrn adapted to contain secondary fiuid, means communicating the high pressure compartment of the casing with the interior of the diaphragm for pressurizing the diaphragm with high pressure from the Upstream compartment, means communicating the portion of the tank eXterior-ly of the diaphragm with the low pressure compart'ment of the casing for admitting secondary fiuid into the downstream compartment, said last named means including fiow restriction means comprising a capillary tube communicated with a port in the downstream compartment of the casing for restricting the fiow of secondary fluid, and means closing the port leading into the downstream chamber from lthe flow restriction means for preventing residual flow of secondary fiuid into the downstream compartment when there is no primary fiuid fiow, said port closing means including a spring urged fiapper valve normally closing the inlet port for the secondary fiuid, a diaphragm ymounted in the porous member and engaged with the fiapper valve, 'and means extending through 'the porous member for communicating the diaphragm with the high pressure compartment whereby pressure of fiow of primary fiuid will cause the diaphragm mounted in the porous member to move the valve away from the inlet port for the secondary fiuid thereby allowing the secondary fiuid to enter the low pressure compartment and to mix with the primary fiuid.

3. The structure as defined in claim 2 wherein said diaphragm is in the form of a bag-like member having a size sufficient to just fill the hollow tank Without being distended thereby eliminating any erroneous proportional fiow caused by any resilient pressure created by the diaphragm were it distended.

4. The combination of claim 3 wherein said casing is provided with a transverse screen on the upstream side of the porous member, and a drain petcock in the casing on the upstream side of the screen for draining foreign materials from the casing before they become embedded in the porous member.

5. The combination of claim 4 wherein said tank is detachable from the casing thereby allowing the pressure tank to be replaced without disturbing any of the structure of the porous member, casing and the like.

6. A fluid proportioning device for introducing a secondary fluid in a substantially constant proportion into a primary fluid comprising a hollow casing interposed in the fluid flow line of the primary fluid, a transversely extending porous member dividing the casing into two compartments with the upstream compa-rtment having a higher pressure than the downstream compartment thereby providing a pressure differential on opposite sides of the porous member, a hollow tank disposed in spaced relation to said casing, said hollow tank including a flexible non-stretchable diaphra'gm, the portion of the tank outwardly of the diap'hragm adapted to contain secondary fluid, means communicating the high pressure compartment of |the casing with the in'terior of the diaphragm -for pressurizing the diaphragm with high pressure from the upstream compartment, means communicating the portion of the tank exteriorly of the diaphragm wtih the llow pressure compartment of the casing for admitting secondary fluid into the downstream compartment, said last n'amed means including flow restriction means comprising a capillary tube communicated with a port in the downstream compartment of the casing for restricting the flow of secondary fluid into lthe downstream compartment. i

7. A fluid proportioning device for introducing a secondary fluid in 'a substantially constant proportion into a primary fluid comprising a hollow casing interposed in the fluid flow line of the primary fluid, a transversely extending porous member dividng the casing into two compartments with the upstream compantment having a higher pressure than the downstrearn compartment thereby providing a pressure diferential on opposite sides of 'the porous member, a hollow tank disposed in spaced relation to said casing, said hollow tank including a flexible non-stretchable diaphragm, the portion of the tank outwardly of the diaphragm adapted to contain secondary fluid, means communicating the high pressure compartment of the casing with the interior of the diaphragm for pressurizing the diaphragm With high pressure from the Upstream compartment, means communicating the portion of the tank exteriorly of the diaphragm with the low pressure compartment of the casing for admitting secondary fluid into the downstrearn compartment, said last named means including a flow restriction device for restricting the flow of secondary fluid during normal operation of the device and stopping flow of secondary fluid when primary fluid flow is lstopped said flow restriction device is in the form of a capillary tube interconnecting the downstream compartment and the portion of the tank exteriorly of the diaphragm.

References Cited in the file of this patent UNITED STATES PATENTS 1,883,720 Grimes Oct. 18, 1932 1,947,586 Fletcher Feb. 20J 1934 2,310,051 B-aer Feb. 2, 1943 2,323,618 Ottoson July 6, 1943 2,573,2,99 Bast Oct. 30, 1951 FOREIGN PATENTS 539,548 Belgium July 30, 1955 

1. A FLUID PROPORTIONING DEVICE FOR INTRODUCING A SECONDARY FLUID IN A SUBSTANTIALLY CONSTANT PROPROTION INTO A PRIMARY FLUID COMPRISING A HOLLOW CASING INTERPOSED IN THE FLUID FLOW LINE OF THE PRIMARY FLUID, A TRANSVERSELY EXTENDING POROUS MEMBER DIVIDING THE CASING INTO TWO COMPARTMENTS WITH THE UPSTREAM COMPARTMENT HAVING A HIGHER PRESSURE THAN THE DOWNSTREAM COMPARTMENT THEREBY PROVIDING A PRESSURE DIFFERENTIAL ON OPPOSITE SIDES OF THE POROUS MEMBER, A HOLLOW TANK DISPOSED IN SPACED RELATION TO SAID CASING, SAID HOLLOW TANK INCLUDING A FLEXIBLE NON-STRETCHABLE DIAPHRAGM, THE PORTION OF THE TANK OUTWARDLY OF TEH DIAPHAGM ADAPTED TO CONTAIN SECONDARY 